Torosaurus

perforated lizard

• toreo · Greek · to pierce, perforate
• sauros · Greek · lizard

The name comes from the Greek "toreo" (to pierce or perforate) plus "sauros" (lizard), referring to the two large openings (fenestrae) in its huge frill. It is often wrongly thought to come from the Spanish/Latin "toro" or "taurus" meaning "bull", but Marsh intended the "perforated" meaning. The frill and skull are among the largest of any known land animal.

Named by

Marsh

Year named

1891

Period

Late Cretaceous

Stage

Maastrichtian

Found in

Lance Formation, Wyoming, USA (type); other specimens from the Hell Creek Formation and other western North American Late Cretaceous formations

A large ceratopsid (horned dinosaur) closely related to Triceratops. Some researchers (e.g. Scannella and Horner, 2010) have argued that Torosaurus represents the mature growth stage of Triceratops, but this is disputed and many workers still treat Torosaurus as a distinct valid genus.